The present invention relates in general to body supporting devices, and more particularly, to mattresses and box springs having an inner coil spring structure and providing adjustable degrees of firmness by employing inflatable elongated pneumatic members arranged within the matrix of the inner coil spring structure.
A variety of mattress constructions are well known, such as the conventional coil spring mattress. Mattresses of the coil spring type are generally supplied in different degrees of firmness. For example, some mattresses are extremely soft and yieldable while others are relatively rigid and unyielding. Very often, a mattress requires a certain degree of rigidity for therapeutic purposes. Once a mattress of a particular firmness has been purchased, it cannot generally be changed without the necessity of having to purchase another mattress. For this reason, users frequently resort to the unsatisfactory technique of placing rigid boards and the like between the mattress and box spring, or within the mattress itself as known from Boyles, U.S. Pat. No. 3,089,154, in an attempt to control firmness.
The problem of supplying mattresses with various degrees of firmness is a considerable one. This applies to manufacturers who are typically required to maintain a large inventory of mattresses with different degrees of firmness. In addition, considerable difficulty arises with respect to hotels and the like which are often required to satisfy the particular requirements or tastes of its guests as to the firmness of the mattress in a particular room. For these reasons, it is desirable to provide a single mattress which easily adjusts to provide different degrees of firmness.
To this end, there is known from Arpin, U.S. Pat. No. 2,779,034, a mattress have an inner coil spring structure which is contained within a flexible, air impermeable cover. The firmness of the mattress is controlled by providing a vacuum within the cover by means of, for example, an ordinary household vacuum cleaner. In Ingram, U.S. Pat. No. 3,303,518 there is known an inflatable air mattress divided internally into separate sections or cells capable of independent inflation so as to vary the degree of softness or firmness to suit individual requirements. A similar inflatable air mattress constructed of individual inflatable cells enclosed within an outer casing is known from Hart, U.S. Pat. No. 1,772,310.
The latter two air mattresses disclosed in the Ingram and Hart patents are of the springless variety, more conventionally known simply as an air mattress and, therefore, do not possess the attributes of the much preferred inner coil spring mattress. To this end, there is known from Cvetkovic, U.S. Pat. No. 4,827,546, a pseudo coil spring mattress employing a plurality of accordian-like flexible bellows, which support an upwardly extending coil spring. The bellows are pressurized using air or water and interconnected in fluid communication with each other. As a result, the mattress vis-a-vis the flexible bellows is able to redistribute the pressure applied to it by the various parts of the human body.
There is further known from Laforest, U.S. Pat. No. 4,357,724 an inner coil spring mattress having adjustable firmness by virtue of the use of a pneumatic core. The pneumatic core is constructed as an inflatable bag, the upper surface being non-elastic, while the lower surface being of elastic rubber material supporting a plurality of protrusions which are adapted to be inserted into the mouth of some of the openings in the coil springs to insure lateral stability of the mattress. There is still further known from Kentor, et al. U.S. Pat. No. 3,608,107, an inner coil spring mattress having adjustable firmness by use of individual plunger mechanisms. Each plunger mechanism is concentrically arranged within a coil spring having adjustable stops to limit the degree of spring compression.
The aforementioned known mattresses having adjustable firmness lack the desired direct inner coil spring body support which can cause discomfort and disruption to the sleeping process. Accordingly, it is an object of the present invention to provide an adjustable firmness mattress having an inner coil spring structure integrated with elongated pneumatic members to enable varying degrees of firmness to promote maximum comfort and body support.
Another object of the present invention is to provide an adjustable firmness mattress which is easy and economical to manufacture.
Another object of the present invention is to provide an adjustable firmness mattress having a generally conventional inner coil spring structure.